Control apparatus



Nov. 16 1926.;-

L. G. RILEY CONTROL APPARATUS Filed Sept. 28 1921 lNVENTOR Lyn/7 ci/fi/ey,

ATTORNEY III WITNESSES: m. $26

Patented 1 Nov. 16, 1926.

UNITED STATES 1,606,808 PATENT OFFICE.

LYNN G. RILEY, OF WILKINSBUBG, PENNSYLVANIA, ABBIG-NOB TO WESTINGHOUSE ILIQIBIO Q: IANUFACTUBING COMPANY, A CORPORATION 01' PINNSYLVANIA.

CONTROL APPARATUS.

I Application filed September 28, 1921. Serial 1T0. 503,874.

This invention relates to devices adapted to rupture electric arcs occurring between two points, such, for example, as contact members of a unit-switch controller or other controller for electric motors.

The object of-my invention is to provide a blowout ma et of improved character which will cou h the paths of arcs within definite limits.

Considerable difliculty has been experienced in the design of magnetic switches or contactors in roviding an arc box or chute of suitable dimensions and in preventing burning of the chute on account of contact with the arc. In certain applications, it is very desirable to reduce the overall height of'the contactors. It is usual to locate the blow-out coil above the switchcontacts.

I propose to divide the blow-out coil into 0 two sections, for convenience, and locate them adjacent to the outer sides of the respective arcing horns. The are chute is then reduced in helght to a minimum sufiicient to accommodate the pole pieces of a blow-out ma et of well-known construction.

band of ma etic material, which is clamped to the po e pieces, entirely encomasses the blow-out magnet. For convenience, I use each blow-out-coil section as a s acer between the band and the pole pieces. ith the common arrangement oi switch contacts which operate in avertical plane, this band is arranged substantially in a vertical position and the upper and the lower ends of the band are of constricted sectional area to permit of leakage of ma etic lines of force which are 0 posite in rection to the lines of force in need bythe blow-out 111 et.

igure 1 is a side view, partially in section and ially in elevation, of apparatus embog ymg my invention.

ig. 2 is a front view, pargi ally in section,-

i 1. l ig. 1, a conof ap aratus illustrated in Re erring particularly to tada'or comprises a stationary contact memher 1 that is supported on an insulating base 2 and a movable contact member 3 t at is pivotally mounted on a shaft 4 and actuated upon the vertical movement of a plunger 5 connected thereto. Suitable contact pressure is maintained by means of acompression spring 6. Arcing horns 7 and 8 are mounted on the stationary and the movable contact members 1 and 3, respectively. A blowout coil'9, comprisin two sections, has one of its terminals bolted to the insulating base 2 and its other terminal connected to the stationary contact member. 1. Pole pieces 11 are attached to core members 12 on which the sections of the blow-out coil are mount,- ed. A band of magnetic material 13 surrounds the blow-out magnet and is fastened to the outer ends of the magnet core members 12. An arc chute 14 su ports' the pole pieces 11 and provides insu ation for both pole/pieces and the band 13.

The contact members 1 and 3 are engaged upon the vertical movement of lung'er' 5, which may be actuated by suita le means, and contact member 3 0 rates with a rolling motion to compress tlib spring 6. Upon the release of plunger 5 and the consequent separation of contact members 1 and 3 to interrupt the circuit traversin these contact members, the current whic also traverses blow-out coil 9 induces a magnetic field in a well known manner. Current carried across the air gap between contact members 1 and 3, and the arc incident thereto is acted upon in a manner similar to that of an armature conductor of an electric motor in its magnetic field. The are is carried "out in apath of bow-shape, with its endis extending around the arcing horns 7 an 8. I

Referring now to Fig. 2, for a predetermined direction of current through the blow-out coil 9, the magnetic lines of force are directed between the le pieces 11 in a direction indicated by t arrowsat the extreme upper and lower edges of the pole pieces. Also, the lines of magnetic force traversin the core members. 12 extend through c band 13 and, on account ofthe restricted cross-sectional areas at the ends of this hand, there will be a leakage of the .lines of magnetic force traversing the air gap at the upper and lower portions of the blow-out magnet which are opposite in di-" rection to the lines offorce between the pole pieces. There is a-neutral point between the fields traversed by these oppositely directed lines of force.

The bow-shape path of the: arc, the ends of which extend along the arcing horns 7 and 8 in a well known manner under the influence of the'field induced between the pole pieces 11, as it approaches the end of duced by the band 13. The lines of force in the latter field are opposite in direction to those in the field impelling the are. As a result, the path of the arc will be directed along the neutral zone between the oppositely directed fields and away from the arc ing horns. The are is, therefore, also restricted in its vertical movement by the reversed field and will not be blown against the upper or lower ends of the arc chute.

Thus, the energization of the magnet coils 9 induces an arc-rupturing field about the contact members 1 and 3 and are horns 7 and 8 which functions to force an are drawn between the contact members outward along the arc horns. The band 13 of magnetic material serves to concentrate the external lines of ma netic force to provide a strong 'magnetic held opposite in direc tion 'to the arc rupturing field. Consequently, a neutral zone is established between the two magnetic fields. I

Since the ends of the band are constricted, there is a great leakage of magnetic flux between the sides of the band near their extremities, thus building up a mag netic field inside the band, thereby locating the neutral zone at a distance from the ends of the band 13 and near the points where the arc horns extend beyond the pole pieces 11. Hence, it will be readily understood that the points at which the arcs are forced to leave the arc horns may be located as desired.

The advantages of equipment of the character described will be at once evident to those familiar with the art. The principles of a single blow-out magnet are well known, but I have succeeded in limiting the path of an electric are by setting up a magnetic field which opposes the force directing the arc in such a manner as to assist in blowing the are free from the live portions of the switch mechanism and also eliminate burning of the arc'chute. As the arrangement of parts illustrated is a matter of convenience and not, to any great extent, a matter of necessity, l: do not wish to be limited to the exact arrangement shown- I claim as my invention:

1- An arc-rupturing device comprising, in combination, a plurality of contact members disposed for relative movement, electr' magnetic means for developing a magnetic field cooperative to rupture an are drawn between the contact members, and means for concentrating the external lines oit magnetic force adjacent said arc-rupturing field to effeet a restriction to the travel of an arc.

2., An arc-raptnr device comprising, in combination, a plurality of contact members disposed for :eelative movement, electromagnetic means to develop a magnetic field cooperative to rupture are drawn between the contact members, and means for concentrating the external lines of magnetic force to provide a magnetic field adjacent and opposite to the arc-rupturing field to effect a restriction to the travel of an arc.

3. An arc-rupturing device comprising,

- in combination, a plurality of contact members disposed for relative movement, a plurality of spaced magnets disposed on opposite sides of said contact members to develop a magnetic field in one direction cooperative to rupture an are drawn between the contact members and means for concentrating the external lines of magnetic force to provide a magnetic field in the opposite direction to said arc-rupturing field, thereby to limit the travel of the are.

4. An arc-rupturing device comprising, in combination, a plurality of contact members disposed for relative movement, a plurality of spaced magnets disposed on 0pposite sides of said contact members to develop a magnetic field in one direction cooperative to rupture an are drawn between the contact members and a band of magnetic material disposed to concentrate the external lines of magnetic force to provide an external magnetic. field in the opposite direction to said arc-rupturing field, thereby to limit the travel of an arc.

5. An arc-rupturing device comprising, in combination, a plurality of contact members disposed for relative movement, a plurality of spaced magnets disposed on opposite sides of said contact members to develop a magnetic field in one direction cooperative to rupture an are drawn between the contact members and a band of magnetic material disposed to concentrate the external lines of ma netic force to provide a magnetic field encircling and in the opposite direction. to the arc-rupturing field, said band being concentrated at predetermined points to develop an internal field at said predetermined points, thereby to restrict the travel of an are.

6. An arc-rupturing device comprising, in combination, a plurality of contact members disposed for relative movement, a plurality of spaced magnets disposed on opposite sides of said contact members to develop a magnetic field in one direction cooperative to rupture an are drawn between said contact members and a rectangular band of magnetic material disposed to' concentrate the external lines of magnetic force, said band being oi smaller cross sectional area at the ends to develop magnetic field'inside the band and in opposition to the arc-rap turing field, thereby to limit the travel of an are, i

7. An arc-rupturing device comprising,

bers, a plurality of spaced magnets disposed on opposite sides of said contact members and are horns to develop a magnetic field in one direction cooperative to rupture an are drawn between said contact members, and a band of magnetic material disposed to concentrate the, external lines of magnetic force to provide an external magnetic field in the opposite direction to said areiupturing field, thereby to provide a neutral zone nearthe ends of said arc horns to limit the travel of an arc- 8. An arc rupturing device comprising, in combination, a plurality of contact members disposed for relative movement, arc

horns to receive arcs from the contact members, a plurality of spaced magnets disposed on opposite sides of said contact members and are horns to develop a magnetic field in one direction cooperative to rupture an are drawn between said contact members, pole pieces carried by said magnets, said are horns etxending beyond said pole pieces, and means for concentrating the external lines of magnetic force adjacent said arcrnpturing field to provide a neutral zone to effect a restriction of the travel of an are along said arc,h0rns.

I In testimony whereof, I have hereunto subscribed my name this 14th day of September, 1921.

LYNN G. RILEY. 

